Bugfix queue timeout
Fixed incorrectly used global variable

The "ser" variable only happens to exist when the module is run
directly,so this obviously breaks as soon as the classes are used
somewhere else. I guess we can file this under copypastafail.
Cleaned up some imports
Emit signals when reading/sending messages
Implemented simple GUI

Mostly migrated from the old C++ application. Currently only includes
the message list which will probably renamed some time in the future.